This invention relates broadly to portable drilling apparatus. It pertains particularly to a guide for mounting a portable drill and guiding its drilling movement in an accurately determined path.
Various guiding systems for portable electric, air and hydraulic drills heretofore have been devised. These in effect convert such drills to portable drill presses. See for example the following U.S. Pat. Nos.: 2,261,746; 2,748,628; 2,622,458; 3,089,357; 2,637,225; 3,250,153.
It is the object of the present invention to provide a drill guide of the class to which these patents are directed, but characterized by the following advantages in that:
1) It supports a portable drill securely and guides it accurately. PA1 2) It causes the drill to drill a straight hole. PA1 3) It is adjustable to various angles. PA1 4) It is adaptable for use on work pieces of various contour, as pipes, channels, and flat work pieces of wood, metal, plastic or other structural materials. PA1 5) It is applicable in any position on the work i.e. at any position inwardly from the edge thereof. PA1 6) It is easily adaptable to application with portable drills of various makes and contour. PA1 7) It may be controlled to drill accurately to a predetermined depth. PA1 8) It is characterized by a simple, effective, gravitational feed. PA1 9) It is useful in drilling a wide range of hole sizes in all desired drill positions. PA1 10) It minimizes the breakage of drill bits. PA1 11) It is simple in construction and positive and easy to operate.
In brief summary, the drill guide of my invention which accomplishes the foregoing and other objects of the invention is adapted for use with a drill having an apertured case or case extension. The guide includes a substantially horizontal base adapted to rest on a selected support. Handle means is integral with the base so that it may be moved from place to place and held during drilling. A standard having a cross section dimensioned for reception in the aperture of the apertured case mounts the drill in relative sliding engagement.
Connecting means, preferably, pivotally adjustable connecting means, connects the standard to the base. Stop means on the standard below the drill arrest the motion of the latter at a predetermined drilling endpoint. Tensioning means interengaging the drill and standard control the sliding motion of the drill, and hence the rate of drilling.